Gaskets are often used as a seal between mating mechanical components. One common application involves gasket placement between the engine block and cylinder head of an internal combustion engine. The engine block and cylinder head are bolted together and the gasket relies on the force of the bolted connection to seal the various openings between the two mating components. In particular, cylinder head gaskets typically extend around cylinder bores to provide a combustion seal, maintaining the high temperature gases of combustion within the cylinder bores. Simultaneously, the gaskets also seal fluid flow openings such as coolant and oil openings to prevent undesirable mixing.
It is typical for a cylinder head gasket to include a main gasket body with a cylinder bore opening, the periphery of which is surrounded by a metallic generally U-shaped flange. The flange engages both the upper face and the lower face of the main gasket body. The flange provides improved protection to the gasket body from the high temperature gases of combustion and serves to dissipate the heat of combustion into the gasket body and away from the cylinder bore opening.
Load bearing coatings have been incorporated onto surfaces of the cylinder head gasket to provide static sealing of joints such as those for which cylinder head gaskets are used. These coatings often contain silicone and normally contain solvents, and require heat to cure. In such a case, the increased sealing property of the silicone is attained at the expense of a decreased load bearing property. Furthermore, the weakness of the coating results in the inability of the gasket to maintain its mechanical structure once the pressure of a load is removed from the gasket. As a result, the gasket must often be replaced when the pressure of a load is removed from the gasket during maintenance or repair of an engine using the gasket.
Accordingly, it is desirable to provide a coating having a high sealing property, increased strength and durability, a high cross-link density when cured, and a good release property. It is also desirable that the coating be readily available for use after long periods of storage. It is further desirable to provide a cylinder head gasket that has a high load bearing characteristic at both high and low temperatures, and adequately seals the joints to which the gasket is mated.